If you zoom in, you’ll see that among the download options, there’s now a “Stanza ePub” button. Press the button to begin downloading (to scroll the list of titles, use a two-fingered vertical drag — again, this is experimental, and we are working on a better iPhone UI).

Pressing that button will open Stanza and download the book.

This kind of integration was simple and straightforward in large part because many of the moving parts around Stanza are based on open standards, including EPUB and the Atom Publishing Protocol (both successful and important XML standards that publishers should be paying attention to — find out more at January’s StartWithXML forum in New York).